Powered toothbrushes have been available for some time. Powered toothbrushes have advantages over manual (non-powered) toothbrushes in that they impart movement to the bristles at much higher speeds than possible manually, and may impart different types and directions of motion. These motions, generally in combination with manual movement of the toothbrush by the user, may provide superior cleaning than manual toothbrushes. Conventional powered toothbrushes are powered by disposable or rechargeable batteries that power an electric motor, which in turn drives the toothbrush head. The batteries of conventional powered toothbrushes are bulky standard-sized batteries that provide enough power for numerous (more than a few) average cleaning sessions without being replaced or recharged.
FIG. 1 shows an example of a powered toothbrush as depicted in U.S. Pat. No. 6,813,793 to Eliav. The toothbrush 5 has a disc-shaped bristle carrier that is driven in a vibrating or oscillating manner along with bristles attached thereto. Toothbrush 5 has a handle portion 10 at a proximal end of the toothbrush and a head 11 at a distal end of the toothbrush. The handle portion 10 has compartments for containing a motor 14 and batteries 15 and 16. The head 11 includes a generally circular bristle holder 13. A rotatable shaft 12 extends from the motor 14 to the head 11. A shaft coupling 17 may be located along the shaft 12 and may be configured to provide for the shaft 12 to be separated at a point between the motor 14 and the head 11. This can permit the shaft to be removed from the toothbrush 5, e.g., for cleaning or replacement.
Batteries 15 and 16 of conventional powered toothbrushes are bulky, standard-sized batteries, such as AA size batteries. The batteries store sufficient power to operate motor 14 for numerous (more than a few) average cleaning sessions without requiring replacement batteries or without recharging the batteries.